Stretchable fabric

ABSTRACT

First warp yarns and second warp yarns are each interwoven with weft yarns to produce a one-layer, lightweight, stretchable fabric. The first warp yarns include stretchable yarns that are activatable to achieve a contracted state, and the second warp yarns include non-stretchable yarns. The first warp yarns may include a stretchable core yarn with non-stretchable wrap yarn wrapped around the stretchable core yarn. The first warp yarns may be in an alternating arrangement with the second warp yarns. When the yarns are woven together, the first warp yarns are in an extended state and the second warp yarns are in an unbunched state. The fabric then undergoes a finishing procedure during which the first warp yarns are activated to achieve a contracted state. The second warp yarns thus achieve a bunched state, and the resulting fabric is stretchable in the warp direction.

BACKGROUND

As textile technology advances, consumers seek fabrics and clothing thatare functional, comfortable, and affordable. For example, policeofficers, military personnel, and other individuals may desire clothingthat is both fire resistant, to guard against exposure to high heat andflames, and stretchable to allow the wearer to perform his/her requiredactivities with relative ease and comfort. A fabric that satisfies theserequirements may thus need to include fabrics that are fire resistant,strong, soft, stretchable, and/or flexible.

Often times, different parts of the same garment are subjected todifferent forces and must withstand different performance conditions,depending on the proximity to a moving body part. For example, fabriclocated near a wearer's joint, such as an elbow or a knee, may oftenexperience greater stresses due to the movement of the wearer's joint asthe wearer conducts work or recreational activities as compared to otherparts of the same garment in other areas, such as the upper arm.

Applicant has discovered then that it would be desirable to provide afabric that can be used to fashion clothes or parts of clothing that arefire resistant, durable, abrasion resistant, stretchable, comfortable,reliable, and/or attractive. As described in greater detail below, avariety of challenges were identified and overcome through Applicant'sefforts to invent and develop such a fabric.

BRIEF SUMMARY OF THE INVENTION

Systems and methods are therefore provided for forming a fabric thatincorporates stretchable and non-stretchable yarns into a unitary,one-layer, lightweight, stretchable fabric.

In some embodiments, a fabric is provided that includes a plurality ofweft yarns, a plurality of first warp yarns interwoven with the weftyarns, and a plurality of second warp yarns interwoven with the weftyarns. The first warp yarns comprise stretchable yarns and areactivatable to achieve a contracted state, and the second warp yarnscomprise non-stretchable yarns. The fabric is stretchable in a warpdirection upon activation of at least some of the plurality of firstwarp yarns. At least some of the plurality of second warp yarns mayachieve a bunched state upon activation of the first warp yarns. Thefirst warp yarns may comprise Lycra, and the second warp yarns maycomprise nylon.

In some cases, at least some of the first warp yarns comprise astretchable core yarn and a non-stretchable wrap yarn wrapped around thestretchable core yarn. The stretchable core yarn may comprise Lycra, andthe non-stretchable wrap yarn may comprise nylon. In some instances, thestretchable core yarn is stretchable to a length between approximately 2and 7 times the respective yarn's original length under tension and iscapable of returning to approximately its original length when no longerunder tension. Similarly, the non-stretchable wrap yarn may be incapableof being stretched to a length greater than approximately 2 times therespective yarn's original length under tension or may be plasticallydeformed when stretched to a length greater than approximately 2 timesthe respective yarn's original length.

The first warp yarns may float at least two of the plurality of weftyarns. Likewise, the second warp yarns may float at least two of theplurality of weft yarns. Furthermore, the weft yarns may befire-resistant. At least some of the first warp yarns may comprisestretchable yarns that are stretchable to a length between approximately2 and 7 times the respective yarn's original length under tension andare capable of returning to approximately its original length when nolonger under tension, and at least some of the second warp yarns maycomprise non-stretchable yarns that are incapable of being stretched toa length greater than approximately 2 times the respective yarn'soriginal length under tension or are plastically deformed when stretchedto a length greater than approximately 2 times the respective yarn'soriginal length.

In other embodiments, a fabric is provided comprising a plurality ofweft yarns, a plurality of first warp yarns interwoven with the weftyarns, and a plurality of second warp yarns interwoven with the weftyarns. The first warp yarns are activatable to achieve a contractedstate, and at least some of the plurality of second warp yarns achieve abunched state upon activation of the first warp yarns. The plurality offirst warp yarns may be in an alternating arrangement with the pluralityof second warp yarns. Furthermore, at least some of the second warpyarns may comprise non-stretchable yarns.

In some cases, at least some of the first warp yarns comprise astretchable core yarn and a non-stretchable wrap yarn wrapped around thestretchable core yarn. The stretchable core yarn may comprise Lycra, andthe non-stretchable wrap yarn may comprise nylon. The non-stretchablewrap yarn may be a first non-stretchable wrap yarn, and at least some ofthe first warp yarns may further comprise a second non-stretchable wrapyarn. The first non-stretchable wrap yarn may be wrapped about thestretchable core yarn in a first direction and the secondnon-stretchable wrap yarn may be wrapped about the stretchable core yarnin a second direction.

The fabric may comprise at least one of an anti-microbial and awater-resistant coating. In some instances, the first warp yarns maycomprise Lycra and the second warp yarns may comprise nylon.Furthermore, the weft yarns may be fire-resistant.

In still other embodiments, a method of weaving a fabric is provided, inwhich a plurality of weft yarns, a plurality of first warp yarns in anextended state, and a plurality of second warp yarns are provided. Thefirst warp yarns are interwoven with the weft yarns, and the second warpyarns are interwoven with the weft yarns. The first warp yarns areactivated to achieve a contracted state of at least some of the firstwarp yarns. As a result, the fabric is stretchable in a warp directionupon activation of at least some of the plurality of the first warpyarns. In some cases, the second warp yarns are provided in an unbunchedstate, and activating the first warp yarns causes at least some of thesecond warp yarns to move from the unbunched state to a bunched state.

At least some of the first warp yarns may comprise a stretchable coreyarn and a non-stretchable wrap yarn wrapped around the stretchable coreyarn. Also, interweaving the first and second warp yarns with the weftyarns may comprise alternately weaving the first and second warp yarns.Furthermore, the fabric may be chemically treated to impartanti-microbial or water-resistant characteristics to the fabric.

In some cases, interweaving the first warp yarns with the weft yarnscomprises floating at least two of the plurality of weft yarns, andinterweaving the second warp yarns with the weft yarns comprisesfloating at least two of the plurality of weft yarns. In addition,providing the plurality of first warp yarns in an extended state maycomprise applying tension to the first warp yarns.

In still other embodiments, a fabric is provided that includes aplurality of weft yarns, a plurality of first warp yarns interwoven withthe weft yarns, and a plurality of second warp yarns interwoven with theweft yarns. The first warp yarns are in a contracted state and arestretchable between the contracted state and an extended state.Furthermore, the second warp yarns are in a bunched state. Thus, whenthe fabric is stretched in the warp direction, the plurality of firstwarp yarns is moved from the contracted state to the extended state, andthe plurality of second warp yarns is moved from the bunched state to anunbunched state.

The amount of stretch of the fabric may be limited by a length of thesecond warp yarns in their respective unbunched states. Also, at leastsome of the first warp yarns may comprise a stretchable core yarn and anon-stretchable wrap yarn wrapped around the stretchable core yarn. Thestretchable core yarn may comprise Lycra, and the non-stretchable wrapyarn may comprise nylon. In some cases, the non-stretchable wrap yarn isa first non-stretchable wrap yarn, and at least some of the first warpyarns further comprise a second non-stretchable wrap yarn. Thus, thefirst non-stretchable wrap yarn may be wrapped about the stretchablecore yarn in a first direction, and the second non-stretchable wrap yarnmay be wrapped about the stretchable core yarn in a second direction.

In other embodiments, a garment is provided, where at least a portion ofthe garment comprises a fabric. The fabric, in turn, comprises aplurality of weft yarns, a plurality of first warp yarns interwoven withthe weft yarns, and a plurality of second warp yarns interwoven with theweft yarns. The first warp yarns are in a contracted state and arestretchable between the contracted state and an extended state, and thesecond warp yarns are in a bunched state. When the fabric is stretchedin the warp direction, the first warp yarns are moved from thecontracted state to the extended state, and the second warp yarns aremoved from the bunched state to an unbunched state.

In some cases, at least some of the first warp yarns comprise astretchable core yarn and a non-stretchable wrap yarn wrapped around thestretchable core yarn. The stretchable core yarn may comprise Lycra, andthe non-stretchable wrap yarn may comprise nylon. Furthermore, thenon-stretchable wrap yarn may be a first non-stretchable wrap yarn, andat least some of the first warp yarns may further comprise a secondnon-stretchable wrap yarn. Thus, the first non-stretchable wrap yarn maybe wrapped about the stretchable core yarn in a first direction, and thesecond non-stretchable wrap yarn may be wrapped about the stretchablecore yarn in a second direction.

Embodiments of the invention in which first warp yarns and second warpyarns are each interwoven with weft yarns to produce a one-layer,lightweight, stretchable fabric are described in greater detail below.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1A depicts a first surface of a fabric structured in accordancewith one exemplary embodiment of the present invention;

FIG. 1B is a schematic representation of the fabric of FIG. 1A;

FIG. 2A depicts a second surface of the fabric of FIG. 1A;

FIG. 2B is a schematic representation of the fabric of FIG. 2A;

FIG. 3A is a schematic representation of a cross-sectional view takenalong a first warp yarn of the fabric along line 3A-3A of FIG. 1B;

FIG. 3B is a schematic representation of a cross-sectional view takenalong a second warp yarn of the fabric along line 3B-3B of FIG. 1B;

FIG. 4 is a schematic representation of a cross-sectional view takenalong a weft yarn of the fabric along line 4-4 of FIG. 1B;

FIG. 5A is a schematic representation of a first warp yarn with astretchable core and a non-stretchable wrap yarn in a relaxed positionstructured in accordance with one exemplary embodiment of the presentinvention;

FIG. 5B is a schematic representation of the first warp yarn of FIG. 5Aunder tension;

FIG. 6A is a schematic representation of a warpwise cross-section of thefabric of FIG. 1B showing the first warp yarn in a contracted state andthe second warp yarn in a bunched state in accordance with one exemplaryembodiment of the present invention;

FIG. 6B is a schematic representation of the cross-section of FIG. 6Ashowing the first warp yarn in an extended state and the second warpyarn in an unbunched state in accordance with one exemplary embodimentof the present invention;

FIG. 7 illustrates clothing made from fabric woven in accordance withone exemplary embodiment of the present invention;

FIG. 8 is a schematic representation of a loom for weaving fabrics inaccordance with one exemplary embodiment of the present invention; and

FIG. 9 is a schematic representation of a first warp yarn with astretchable core and two non-stretchable wrap yarns in accordance withone exemplary embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention now will be described more fullyhereinafter with reference to the accompanying drawings, in which some,but not all, embodiments of the invention are shown. Indeed, embodimentsof the invention may be in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will satisfy applicablelegal requirements. Like reference numerals refer to like elementsthroughout.

Various embodiments of the present invention are directed to a fabricthat is structured to use and combine multiple yarns each selected toprovide the fabric with specific qualities, characteristics, and/orfunctions. For example, fabrics structured in accordance with thepresent invention may include yarns selected to impart fire resistance,strength, durability, and/or abrasion resistance to the fabric. Otheryarns may be selected to impart comfort, breatheability, drapeability,and/or stretchability to the fabric. Still other yarns may be selectedto improve the fabric's aesthetic appearance.

In developing fabrics comprised of multiple yarns as discussed above,Applicant discovered that by using a first yarn selected to provide afirst quality (e.g., fire resistance), Applicant may inherently beundermining another desired quality (e.g., stretchability or aestheticappeal). For example, by using modeacrylic fibers for their fireresistance qualities, Applicant may necessarily be introducing a yarn tothe fabric that has poor stretchability. As discussed in greater detailbelow, various embodiments of the present invention are structured tolimit such counter-productive effects.

The specification refers for illustration purposes to various textilerelated terms. For example, the terms “warp” and “weft” are used whendescribing woven fabrics structured in accordance with variousembodiments of the present invention. The term “warp” refers to fibersor yarns that run in the lengthwise or machine direction of the fabric.The term “weft” refers to the fill fibers or yarns that run in acrosswise direction that is transverse to the machine direction of thefabric. Individual weft yarns may be referred to herein as “picks.” Acollection of warp yarns having the same weave structure orconfiguration is referred to herein as a warp system. As illustrated anddescribed below with reference to the figures, warp yarns may beclassified as having the same weave structure (and thus part of the samewarp system) in situations where the weave structure is shifted withrespect to adjacent yarns. The term “yarn” is used throughout thespecification to denote a component of the fabric that is interwovenwith other components to form the fabric. For example, yarns or threadscan include monofilament fibers, multifilament fibers, threads, yarns,staple fibers, composite fibers, and so on.

FIGS. 1A, 1B, 2A, and 2B depict a woven fabric 10 according to anexemplary embodiment, with FIGS. 1A and 1B depicting a first surface 20and FIGS. 2A and 2B depicting a second surface 25. For purposes ofexplanation, reference axes are provided on FIGS. 1A, 1B, 2A, and 2B,with the warp yarns extending along the x-axis and the weft yarnsextending along the y-axis. The z-axis in FIGS. 1A, 1B, 2A, and 2Bextends out of the page. FIGS. 3A and 3B illustrate a warpwisecross-section of the fabric 10 taken along lines 3A-3A and 3B-3B,respectively, of FIG. 1B, or in the x-z plane, and FIG. 4 illustrates aweftwise cross-section of the fabric taken along line 4-4 of FIG. 1B.Thus, in FIGS. 3A and 3B the y-axis extends into the page, and in FIG. 4the x-axis extends out of the page.

Turning to FIG. 1B, in an exemplary embodiment, the depicted wovenportion of fabric 10 includes a plurality weft yarns 30 and two warpsystems 40, 45. As described in greater detail below, the first warpyarns 40 may be interwoven with the weft yarns 30, and the second warpyarns 45 may be interwoven with the weft yarns 30 in accordance withembodiments of the present invention to produce a one-layer fabric thatis stretchable in a warp direction (i.e., along the x-axis) uponactivation of at least some of the plurality of first warp yarns. Thus,Applicant has discovered that in forming a fabric having the structuredescribed below, the first and second warp yarns 40, 45 can be selectedand configured with respect to each other to allow the fabric to stretchin the warp direction while the weft yarns 30 may be selected to provideother performance characteristics, such as fire resistance, to thefabric without regard to the stretchability of the weft yarns.

FIGS. 3A and 3B show cross-sections of the depicted fabric portion 10taken along one of the first warp yarns 40 and one of the second warpyarns 45, respectively. For ease of explanation, 6 weft yarns 30 areshown arranged in a single row. The 6 weft yarns have been sequentiallyidentified for illustration purposes and are referred to herein as “picka,” “pick b,” “pick c,” “pick a,” “pick b,” and “pick c.” Although thefigures depict the diameters of the warp yarns and the weft yarns to besimilar, the diameters of the yarns may be the same or different and arenot limited to the schematic representation provided in the figures. Forexample, the first and/or second warp yarns may have a larger diameterthan the weft yarns, or vice versa. In addition, although the figuresdepict a single yarn for each of the two warp systems 40, 45, one ormore of the warp systems may include multiple yarns, as discussed below.

In the depicted embodiment, each of the first warp yarns 40 isstructured to pass over two weft yarns (e.g., picks c and a) and underone weft yarn (e.g., pick b) in a configuration that may be repeatedthroughout the fabric, as shown in FIG. 3A. Similarly, in FIG. 3B, eachof the second warp yarns 45 is structured to pass over two weft yarns(e.g., picks b and c) and under one weft yarn (e.g., pick a). As aresult of this configuration, a cross-section taken along a weft yarn 30also presents a “two float” structure, as shown in FIG. 4. The “twofloat” structure of FIGS. 3A, 3B, and 4 could be replaced with a threefloat structure (i.e., the first and/or second warp yarns pass overthree picks before proceeding under one) or other weave structureshaving greater or fewer numbers of floats depending upon fabric designrequirements, as will be understood by one of ordinary skill in the artin light of this disclosure. For example, in other embodiments, warpsystems having three or more floats may be used to provide greaterflexibility, stretch, and/or drapeability to the fabric. Furthermore, insome embodiments, different warp systems may have a different number offloats. For example, the first warp yarns 40 may be woven to incorporatetwo floats, whereas the second warp yarns may be woven to include threeor more floats.

The repeated weave structure of the two warp systems 40, 45 may beshifted in the warp direction (along the x-axis direction), for example,when cross-sections taken at different weftwise positions (positionsalong the y-axis) of the fabric are compared, resulting in a tweedpattern of the fabric. The depicted construction, however, is only oneexample of a weave structure of the fabric. Embodiments may includenumerous other basic and complex constructions, as will be understood byone skilled in the art in light of this disclosure.

In some embodiments, the first warp yarns 40 are in an alternatingarrangement with the second warp yarns 45. Thus, as shown in FIGS. 1Band 2B, a single first warp yarn 40 may alternate with a single secondwarp yarn 45 such that each first warp yarn is adjacent two second warpyarns, one on either side (except perhaps at the boundaries of thefabric). In another embodiment, however, the weftwise pattern mayinclude 2 first warp yarns 40 alternating with a single second warp yarn45, 2 first warp yarns alternating with 2 second warp yarns, 3 firstwarp yarns alternating with 1 second warp yarn, 1 first warp yarnalternating with 3 second warp yarns, and so on, as dictated by thewearer's performance needs, the desired aesthetic appearance of thefabric, and other design considerations.

Referring again to FIG. 1B, some of the warp yarns may be stretchable,and others of the warp yarns may be non-stretchable, or at least may notbe as stretchable as the stretchable yarns (i.e., may exhibit somestretchability, but not as much as the stretchable yarns). Inparticular, the first warp yarns 40 may comprise stretchable yarns, forwhich a force applied along the axis of the stretchable yarn results ina temporary lengthening of the yarn (i.e., elastic deformation), withthe yarn returning to approximately its original length once the forceis removed. For example, a stretchable yarn may be a yarn that can bestretched to approximately 200% to 700% of its original length (i.e., 2to 7 times its original length) under tension and returns toapproximately its original length when no longer under tension. Examplesof stretchable yarns include Spandex or elastane fibers, such as Lycra®and Dorlastan® fibers, latex, and polyurethane rubber fibers.

At least some of the second warp yarns 45 may comprise non-stretchableyarns. Non-stretchable yarns are yarns that exhibit little or nostretchability. For example, a non-stretchable yarn may be a yarn thatstretches to less than twice its original length under tension (e.g., ayarn that fractures or breaks when stretched to, for example, 1.5 timesits original length) or a yarn that, once lengthened under tension, ispermanently elongated (i.e., plastically deformed) and does not have theelasticity to return to approximately its original length after theforce is removed. In other words, although the yarn may not remain atits extended length once the tensile force is removed, it is not able tofully return to approximately its original (e.g., pre-tension) length.

Nylon 6 and Nylon 6,6, for example, are 100% elastic only when extendedto a length that is less than 1.08 times the original yarn's length.Beyond this extension, such yarns undergo plastic deformation and arethus characterized herein as non-stretchable yarns. Similarly,texturized nylon yarns are typically stretchable in the range ofapproximately 1.06 to 1.34 times the yarn's original length. Otherexamples of non-stretchable yarns include cotton, wool, rayon, polyamidfibers, modeacrylic fibers, high modulus fibers, Kevlar® fibers, Nomex®fibers, high molecular weight polyethylene, aramids, fiberglass, andcarbon fibers. Thus, such yarns are not stretchable relative to theyarns described above that are stretchable yarns, such as Lycra® yarns.

In another aspect of the depicted embodiment, the weft yarns may befire-resistant. For example, the weft yarns may be modacrylic fibersthat exhibit fire-resistant properties, but are non-stretchable. In thisway, the fabric may be useful in garments designed for exposure to highheat and/or fire, such as in certain military or fire-fightingapplications.

In some embodiments, each first warp yarn 40 may comprise two yarns(e.g., in parallel, twisted, wrapped, etc.) that are interwoven with theweft yarns 30 in the same manner as described above. In particular, insome embodiments, at least some of the first warp yarns 40 comprise astretchable core yarn 41 and a non-stretchable wrap yarn 42 wrappedaround the stretchable core yarn, as illustrated in FIG. 5A. Forexample, the stretchable core yarn 41 may be Lycra® fiber or a Lycra®fiber blend, whereas the non-stretchable wrap yarn 42 may be nylon.Although in this example a stretchable yarn (i.e., the stretchable coreyarn 41) is arranged with a non-stretchable yarn (i.e., thenon-stretchable wrap yarn 42), the resulting first warp yarn 40 may bestretchable to approximately 1.05 to 2 times its original length. Thisis because as the stretchable core yarn 41 lengthens under tension (FIG.5B), the non-stretchable wrap yarn 42 “straightens out” to allow for thelengthening of the core yarn. In other words, the number of turns of thenon-stretchable wrap yarn 42 per unit length of the core yarn 41decreases as the core yarn is stretched, and the first warp yarn 40 as awhole increases in length as tension is applied. Although thestretchable core yarn 41 may be stretchable alone to 4 times itsoriginal length, for example, a first warp yarn 40 comprised of astretchable core yarn 41 and a non-stretchable wrap yarn 42 may only bestretchable to 1.3 times its original length. This limitation may beadjusted based on the length of the wrap yarn and the density of thewrapping about the core (e.g., the number of turns per unit length).Thus, the greater the density of the wrapping about the core, the lowerthe stretchability of the resulting first warp yarn 40.

The length of the non-stretchable wrap yarn 42 is thus generally greaterthan the length of the stretchable core yarn 41, for example to accountfor the number of turns of the wrap yarn per unit length of the coreyarn. In addition, in some cases, multiple non-stretchable wrap yarns 42are wrapped around the stretchable core yarn 41 in an effort to balancethe forces on the core yarn. For example, referring to FIG. 9, a firstwrap yarn 42 a may be wrapped from left to right about the core yarn 41,and a second wrap yarn 42 b may be wrapped from right to left over thefirst wrap yarn 42 a and the core yarn. In this way, the forces exertedon the core yarn 41 by the first wrap yarn 42 a are counteracted and/or“balanced” by the second wrap yarn 42 b wrapped in the oppositedirection, giving the fabric additional stability (e.g., preventingrolling of the fabric).

Turning again to FIG. 1B, the first warp yarns 40 may be interwoven withthe weft yarns 30 in an extended state and may be activatable to achievea contracted state. For example, the first warp yarns 40 may be treated(e.g., chemically treated) such that each first warp yarn has a tendencyto remain in the extended state without the application of any, or asmuch, tensile force. In addition, during the weaving process, the firstwarp yarns 40 may be held in tension to achieve the extended state.Thus, in some embodiments (e.g., embodiments in which the first warpyarn 40 comprises a stretchable core yarn 41 and a non-stretchable wrapyarn 42), the length of each first warp yarn 40 in the extended statemay be approximately 1.1 to 2.5 times its original, or contracted,length, depending on the amount of stretchability to be imparted to thefinished fabric for a particular application. The first warp yarns 40may thus be activatable to change state from the extended state to thecontracted state. In other words, in the extended state, even after thetension applied to the first warp yarns 40 during the weaving process isremoved, the first warp yarns may have a tendency to remain relativelyelongated due to the treatment that the yarn was subjected to prior toweaving. Upon activating the first warp yarns 40, however, the firstwarp yarns may “shrink” from the extended state to achieve theircontracted state.

In one embodiment, activation of the first warp yarns 40 occurs during afinishing procedure that the fabric undergoes after the first warpyarns, the second warp yarns 45, and the weft yarns 30 have beeninterwoven to form the fabric. The finishing procedure may entailwashing the fabric for a short duration at a temperature ofapproximately 100° C., which may cause the first warp yarns 40 to changefrom the extended state to the contracted state.

Turning to FIGS. 6A and 6B, in contrast to the extended state of thefirst warp yarns 40, the second warp yarns 45 may be provided in anunbunched, or relaxed, state for interweaving with the weft yarns 30. Asa result of the change of state of the first warp yarns 40 from theextended state to the contracted state, however, the second warp yarns45 are changed from the unbunched state (FIG. 6B) to a bunched state(FIG. 6A). Thus, the terms “extended” and “unbunched” as used hereinrefer to a state of the first warp yarns 40 and second warp yarns 45,respectively, in which the respective yarns achieve a relatively longerlength. Conversely, the terms “contracted” and “bunched” as used hereinrefer to a state of the first warp yarns 40 and second warp yarns 45,respectively, in which the respective yarns achieve a relatively shorterlength.

More specifically, the second warp yarns 45 may be in a bunched state inthe finished fabric, as shown in FIG. 6A, such that each of the secondwarp yarns is not at its original unbunched length l_(u), but rather isheld at a reduced or shortened bunched length l_(b) by the elastic forceF₁ of the first warp yarns 40 to remain in the contracted state. In somecases, the bunched length l_(b) of the second warp yarns 45 in theirbunched state is between approximately 20% and 80% of the unbunchedlength l_(u), for example between approximately 70% and 75% of l_(u). Asa result of this configuration of the second warp yarns 45 with respectto the first warp yarns 40, the finished fabric 10 is stretchable in thewarp direction to between approximately 1.1 and 2 times its originaldimension in the warp direction, for example between approximately 1.1and 1.42 times its original warp dimension (i.e., between 10% and 42%stretch).

Thus, the bunched configuration of the second warp yarns 45 within thefinished fabric 10 allows the first warp yarns 40 to stretch, therebyallowing the fabric as a whole to be stretchable in the warp direction.In other words, as the first warp yarns 40 are stretched (e.g., when atensile force F₂ is applied to the fabric, for example, due to thewearer's activity), the second warp yarns 45 are correspondingly movedfrom the bunched state to the unbunched state. The extent of thefabric's stretchability may be limited by the unbunched length l_(u), ofthe second warp yarns 45. Thus, once the second warp yarns 45 haveachieved their unbunched length l_(u), the fabric 10 generally cannot bestretched further, even if, individually, the first warp yarns 40 arecapable of additional stretch.

As mentioned above, in some embodiments, one or more warp system yarnsmay include a stretchable yarn to provide flexibility to the fabric. Forexample, the first warp yarns 40 may be comprised of or include Lycra®yarns, whereas the second warp yarns 45 may include non-stretchableyarns. In still other embodiments of the present invention, the secondwarp yarns 45 and the weft yarns 30 may be chosen to perform certainfunctions without regard to the inherent stretchability of theparticular yarn. In other words, because of the configuration andarrangement of the first and second warp yarns 40, 45 with respect toeach other and the weft yarns 30, the second warp yarns 45 may beselected for their performance characteristics (for example, strength orabrasion resistance), and the weft yarns may be selected for their fireresistance. Thus, the warpwise stretchability of the fabric will begenerally based on the stretchability of the first warp yarns 40 and thedifference between the bunched length l_(b) as compared to the unbunchedlength l_(u) of the second warp yarns 45.

In one exemplary embodiment, a one-layer stretch, light weight, fireresistant fabric, such as may be suitable for forming outerwear formilitary applications, may be comprised as follows. In this embodiment,one or more of the warp systems may be composite yarns made of 50% nylonand 50% Lycra® fibers. For example, the first warp yarns 40 may be madeof nylon filaments wrapped in two directions over a Lycra® fiber core toform the composite yarn, as discussed above. The second warp yarns 45may be nylon yarns. The yarns in this example may have variousthicknesses, such as 40 denier, 60 denier, or 120 denier Lycra® yarn and70 denier, 100 denier, or 150 denier nylon yarn, among otherthicknesses. The warp systems may each comprise the same nylon-Lycra®fiber blend, or different materials can be used in one or two of thewarp systems to provide for different performance characteristics basedon the intended use of the fabric. Other yarns that may be used in thewarp systems include, for example, cotton, rayon, polyester, nylon,acrylic, and polypropylene, among others. In this exemplary embodiment,the weft yarns may be made of fire resistant yarns, such asmonofilament, multifilament in a continuous filament process, or staplefibers, such as in ring spinning or open end spinning systems. Such fireresistant yarns may include, for example, wool, modacrylic, fireresistant rayon, fire resistant polyester, Kevlar® fibers, Nomex®fibers, metallic fibers, fiberglass, and polybenzimidazole (PBI), amongothers.

In this regard, the yarns of the warp and weft systems may be woventogether as described above to form a fabric of twill constructioncontaining 74% modacrylic fibers, 24% nylon, and 2% Lycra® fibers. Thefinished fabric width may be between 57 inches and 60 inches with athickness of approximately 0.84 mm, and the fabric may weighapproximately 8.5 oz. per square yard. In addition to having fireresistant characteristics, the resulting fabric of the exemplaryembodiment is stretchable in the warp direction, providing enhancedflexibility and comfort to the wearer.

As mentioned above, once the first warp yarns 40, the second warp yarns45, and the weft yarns 30 are woven together, the fabric may besubjected to a finishing procedure to create the finished fabric 10. Inaddition to effecting the activation of the first warp yarns 40 from theextended state to the contracted state, and the resulting change of thesecond warp yarns 45 from the unbunched state to the bunched state, thefinishing procedure may also serve to impart other desiredcharacteristics to the fabric, according to the user's requirements. Forexample, the finishing procedure may include chemically treating thefabric to provide an anti-microbial coating. As another example, thefinishing procedure may make the fabric water-resistant or waterproof.In still another example, the finishing procedure may provide the fabricwith stain-release capabilities, in addition to numerous other qualitiesas will be recognized by one skilled in the art in light of thisdisclosure. Furthermore, the fabric 10 may be dyed or printed upon toprovide the fabric with a desired aesthetic appearance. For example, inmilitary applications, the finished fabric may have a camouflage patternprinted upon its surface to aid the wearer in military activities.

In addition to the stretchability of the first warp yarn 40, the lengthof the first warp yarn in the extended state, and the length of thesecond warp yarn in the unbunched state, the density of the weave alsoplays a role in the resulting stretchability of the finished fabric 10.For example, a more densely woven fabric (i.e., less space between theyarns) would provide for less stretchability in the finished fabric,whereas a less densely woven fabric (i.e., more space between the yarns)would provide for greater stretchability in the finished fabric. Thus,based on the preferences of the wearer and the particular applicationfor which the fabric will be used, the materials selected for the firstand second warp yarns, the configuration of the first and second warpyarns, and the weave density can be customized and adjusted to producefabrics with varying degrees of stretchability.

Referring now to FIG. 7, embodiments of the resulting stretchable fabricmay be used to fashion various types of clothing in accordance withembodiments of the present invention. For example, the fabric can beused to fashion pants, overcoats, shirts, and undergarments, among manyother forms of clothing. In particular, embodiments of the stretchablefabric 10 may be used in certain portions of typical garments thatrequire, for example, additional stretch capabilities with respect tothe rest of the garment. For example, embodiments of the stretchablefabric may be used to fortify, enhance, or repair high-stress areas ofthe garment, such as proximate the elbow 80 the knee 50, pockets 60,and/or the posterior area 65 of pants. Thus, the stretchability providedby the stretchable first warp yarns 40 and the configuration of thefirst warp yarns with respect to the second warp yarns 45 of the fabricmay allow the wearer to move freely while wearing the garment, whereasthe selection of an appropriate non-stretchable yarn for the second warpyarns can impart other desired characteristics to the region 80, 50, 60,65, such as the ability to aesthetically match or resemble the rest ofthe garment.

For example, in an embodiment in which the first warp yarns 40 are nylonyarns wrapped around a Lycra® yarn core and the second warp yarns 45 arenylon yarns, a “patch” may be made that is both stretchable and has asmooth, unobtrusive look. In other words, rather than be compelled touse solely Lycra® yarns in the warp direction to provide the desiredstretchability, which would result in a rough or unfinished-lookingpatch, by incorporating nylon as a wrap yarn 42 in the first warp yarn40 and as the second warp yarn 45, the finished fabric portion may havea smooth appearance to match the surface of the remainder of thegarment. In addition, the strength of the nylon yarn in turn givesmechanical strength properties to the fabric portion for preventing orreducing cuts and tears through the fabric. In this way, the fabric canbe dyed or printed upon in any color to match the look of the clothing.In addition, a yarn such as nylon may also impart additional strengthcharacteristics to the garment in the high-stress areas where it is mostneeded. Furthermore, in some embodiments, the configuration of thefabric and selection of yarns provides a lightweight material to allowthe wearer additional performance flexibility.

As will be apparent to one of skill in the art upon reviewing thisdisclosure, fabrics configured in accordance with various embodiments ofthe present invention may be structured to provide more flexible,aesthetically pleasing materials that are customizable for use in anumber of applications. In addition to selecting the appropriatematerial for each of the first and second warp yarns 40, 45 to providethe desired performance characteristics, additional (i.e., third,fourth, etc.) warp yarns may be selected and incorporated into theone-layer stretchable fabric according to the embodiments describedabove.

The fabric structure 10 described above can be formed using an apparatussuch as the loom 100 shown in FIG. 8. The loom 100 includes a first beam105 holding a supply of warp yarns, such as the first warp yarns 40, anda second beam 110 holding another supply of warp yarns, such as thesecond warp yarns 45. The first and second beams 105, 110 may bepositively driven to advance the warp yarns 40, 45 through the loom 100to a fabric take-up area 115. As will be apparent to one of skill in theart in view of this disclosure, the warp yarns 40, 45 are fed throughheddles 120, each heddle being supported by a frame 125. One or moregrippers 130 are used to pull the weft picks 30 through the shed that iscreated by the movement of the frames 125 and heddles 120. As will befurther appreciated by one of ordinary skill in the art, the loom 100may include hundreds of beams and frames to provide for the weaving oflarge portions of fabric. Thus, FIG. 5 provides a very simplifiedillustration for the purposes of explanation, only.

Furthermore, as noted above, in some embodiments, the first warp yarns40 held on the first beam 105 are in an extended state, such that thefirst warp yarns are advanced through the loom 100 and interwoven withthe second warp yarns 45 and weft yarns 30 while in the extended state.Once the woven fabric has advanced to the take-up area 115, the fabricmay then be transported to a finishing station 140 (shown schematicallyin FIG. 8), where the fabric is subjected to a finishing procedure. Asdiscussed above, the finishing process thus activates the first warpyarns 40, changing the first warp yarns from the extended state to thecontracted state and resulting in the second warp yarns 45 changing fromthe unbunched to the bunched state, thereby providing “built-in”stretchability to the fabric.

Depending on the choice of yarns for weaving the fabric, the fabric maybe optimized for particular applications and may exhibit desirablechemical, electrical, thermal, mechanical, and/or physical properties asneeded. As such, the fabric can be used to form clothing for variouspurposes, such as protective clothing for motorcycle operators andconstruction workers, flame-resistant and/or armored clothing for lawenforcement, military personnel, and other types of clothing that may bedesigned to protect the wearer from one or more particular environmentalconditions.

Although embodiments of the fabric discussed above are configured forproviding warpwise stretchability, it is understood that the conceptsdescribed above can similarly be applied for producing a fabric that isstretchable only in the weft direction or in both the warp and weftdirections. Thus, in some embodiments, at least some of the weft yarnsmay include stretchable yarns and the warp yarns may be selected withoutregard to stretchability, or both the weft and warp yarns may includestretchable yarns, as will be understood by one skilled in the art inlight of this disclosure.

Many modifications and other embodiments of the invention set forthherein will come to mind to one skilled in the art to which theinvention pertains having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the invention is not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1. A fabric comprising: a plurality of weft yarns; a plurality of firstwarp yarns interwoven with the weft yarns, wherein the first warp yarnscomprise stretchable yarns and are activatable to achieve a contractedstate; and a plurality of second warp yarns interwoven with the weftyarns, wherein the second warp yarns comprise non-stretchable yarns;wherein the fabric is stretchable in a warp direction upon activation ofat least some of the plurality of first warp yarns.
 2. The fabric ofclaim 1, wherein at least some of the plurality of second warp yarnsachieve a bunched state upon activation of the first warp yarns.
 3. Thefabric of claim 1, wherein at least some of the first warp yarnscomprise a stretchable core yarn and a non-stretchable wrap yarn wrappedaround the stretchable core yarn.
 4. The fabric of claim 3, wherein thestretchable core yarn comprises Lycra and the non-stretchable wrap yarncomprises nylon.
 5. The fabric of claim 3, wherein the stretchable coreyarn is stretchable to a length between approximately 2 and 7 times therespective yarn's original length under tension and is capable ofreturning to approximately the respective yarn's original length when nolonger under tension, and wherein the non-stretchable wrap yarn isincapable of being stretched to a length greater than approximately 2times the respective yarn's original length under tension or isplastically deformed when stretched to a length greater thanapproximately 2 times the respective yarn's original length.
 6. Thefabric of claim 1, wherein the first warp yarns comprise Lycra and thesecond warp yarns comprise nylon.
 7. The fabric of claim 1, wherein thefirst warp yarns float at least two of the plurality of weft yarns. 8.The fabric of claim 1, wherein the second warp yarns float at least twoof the plurality of weft yarns.
 9. The fabric of claim 1, wherein theweft yarns are fire-resistant.
 10. The fabric of claim 1, wherein atleast some of the first warp yarns comprise stretchable yarns that arestretchable to a length between approximately 2 and 7 times therespective yarn's original length under tension and are capable ofreturning to approximately the respective yarn's original length when nolonger under tension, and wherein at least some of the second warp yarnscomprise non-stretchable yarns that are incapable of being stretched toa length greater than approximately 2 times the respective yarn'soriginal length under tension or are plastically deformed when stretchedto a length greater than approximately 2 times the respective yarn'soriginal length.
 11. A fabric comprising: a plurality of weft yarns; aplurality of first warp yarns interwoven with the weft yarns, whereinthe first warp yarns are activatable to achieve a contracted state; anda plurality of second warp yarns interwoven with the weft yarns; whereinat least some of the plurality of second warp yarns achieve a bunchedstate upon activation of the first warp yarns.
 12. The fabric of claim11, wherein the plurality of first warp yarns are in an alternatingarrangement with the plurality of second warp yarns.
 13. The fabric ofclaim 11, wherein at least some of the plurality of second warp yarnscomprise non-stretchable yarns.
 14. The fabric of claim 11, wherein atleast some of the first warp yarns comprise a stretchable core yarn anda non-stretchable wrap yarn wrapped around the stretchable core yarn.15. The fabric of claim 14, wherein the stretchable core yarn comprisesLycra and the non-stretchable wrap yarn comprises nylon.
 16. The fabricof claim 14, wherein the non-stretchable wrap yarn is a firstnon-stretchable wrap yarn, and wherein at least some of the first warpyarns further comprise a second non-stretchable wrap yarn, wherein thefirst non-stretchable wrap yarn is wrapped about the stretchable coreyarn in a first direction and the second non-stretchable wrap yarn iswrapped about the stretchable core yarn in a second direction.
 17. Thefabric of claim 11, wherein the fabric comprises at least one of ananti-microbial and a water-resistant coating.
 18. The fabric of claim11, wherein the first warp yarns comprise Lycra and the second warpyarns comprise nylon.
 19. The fabric of claim 11, wherein the weft yarnsare fire-resistant.
 20. A method of weaving a fabric comprising:providing a plurality of weft yarns; providing a plurality of first warpyarns in an extended state; providing a plurality of second warp yarns;interweaving the first warp yarns with the weft yarns; interweaving thesecond warp yarns with the weft yarns; and activating the first warpyarns to achieve a contracted state of at least some of the first warpyarns, wherein the fabric is stretchable in a warp direction uponactivation of at least some of the plurality of the first warp yarns.21. The method of claim 20, wherein providing the plurality of secondwarp yarns comprises providing the second warp yarns in an unbunchedstate, and wherein activating the first warp yarns causes at least someof the second warp yarns to move from the unbunched state to a bunchedstate.
 22. The method of claim 20, wherein at least some of the firstwarp yarns comprise a stretchable core yarn and a non-stretchable wrapyarn wrapped around the stretchable core yarn.
 23. The method of claim20, wherein interweaving the first and second warp yarns with the weftyarns comprises alternately weaving the first and second warp yarns. 24.The method of claim 20 further comprising chemically treating the fabricto impart anti-microbial or water-resistant characteristics to thefabric.
 25. The method of claim 20, wherein interweaving the first warpyarns with the weft yarns comprises floating at least two of theplurality of weft yarns, and wherein interweaving the second warp yarnswith the weft yarns comprises floating at least two of the plurality ofweft yarns.
 26. The method of claim 20, wherein providing a plurality offirst warp yarns in an extended state comprises applying tension to thefirst warp yarns.
 27. A fabric comprising: a plurality of weft yarns; aplurality of first warp yarns interwoven with the weft yarns, whereinthe first warp yarns are in a contracted state, the first warp yarnsbeing stretchable between the contracted state and an extended state;and a plurality of second warp yarns interwoven with the weft yarns,wherein the second warp yarns are in a bunched state, wherein, when thefabric is stretched in the warp direction, the plurality of first warpyarns is moved from the contracted state to the extended state and theplurality of second warp yarns is moved from the bunched state to anunbunched state.
 28. The fabric of claim 27, wherein the amount ofstretch of the fabric is limited by a length of the second warp yarns intheir respective unbunched states.
 29. The fabric of claim 27, whereinat least some of the first warp yarns comprise a stretchable core yarnand a non-stretchable wrap yarn wrapped around the stretchable coreyarn.
 30. The fabric of claim 29, wherein the stretchable core yarncomprises Lycra and the non-stretchable wrap yarn comprises nylon. 31.The fabric of claim 29, wherein the non-stretchable wrap yarn is a firstnon-stretchable wrap yarn, and wherein at least some of the first warpyarns further comprise a second non-stretchable wrap yarn, wherein thefirst non-stretchable wrap yarn is wrapped about the stretchable coreyarn in a first direction and the second non-stretchable wrap yarn iswrapped about the stretchable core yarn in a second direction.
 32. Agarment, at least a portion of the garment comprising a fabric, whereinthe fabric comprises: a plurality of weft yarns; a plurality of firstwarp yarns interwoven with the weft yarns, wherein the first warp yarnsare in a contracted state and are stretchable between the contractedstate and an extended state; and a plurality of second warp yarnsinterwoven with the weft yarns, wherein the second warp yarns are in abunched state, wherein, when the fabric is stretched in the warpdirection, the first warp yarns are moved from the contracted state tothe extended state and the second warp yarns are moved from the bunchedstate to an unbunched state.
 33. The garment of claim 32, wherein atleast some of the first warp yarns comprise a stretchable core yarn anda non-stretchable wrap yarn wrapped around the stretchable core yarn.34. The garment of claim 33, wherein the stretchable core yarn comprisesLycra and the non-stretchable wrap yarn comprises nylon.
 35. The garmentof claim 33, wherein the non-stretchable wrap yarn is a firstnon-stretchable wrap yarn, and wherein at least some of the first warpyarns further comprise a second non-stretchable wrap yarn, wherein thefirst non-stretchable wrap yarn is wrapped about the stretchable coreyarn in a first direction and the second non-stretchable wrap yarn iswrapped about the stretchable core yarn in a second direction.